1. Being an Ally of the US doesn't make a nation or regime less of a dictatorship. The United States is responsible for more than a few dictatorships around the world and certainly has no qualms about shaking hands with preexisting dictatorships when oil, currency, etc. are involved.
2. Saying Lindsey Graham endorsed someone with money is a worthless statement. If anything, it just makes people like Saudi Arabia less. Lindsey Graham is widely reviled and believed by many to be a key example of the worst of what American politics have to offer
3. I was a member of the United States military, and can confidently state that despite funding 'counter-terrorism' efforts in that region, there is no love between the US military and KSA. Our government is capable of compartmentalization and is more than willing to send money to less-than-ideal allies to secure other key geo-political objectives.

I have plenty of problems with Israel, including their interactions with Palestine, and am definitely not employed by them either. They have more than their own fair share of atrocities - but those atrocities do not in any way detract from the fact that KSA is a dictatorship that the US props up to maintain its interest in that region. Still 'fuck them'. Done engaging here.